/**
 * 百度地图投影转换库
 *
 * Created by LuLihong on 2023/03/03
 */


(function () {
	const forEachPoint = function (func) {
		return function (input, opt_output, opt_dimension) {
			let len = input.length;
			let dimension = opt_dimension ? opt_dimension : 2;
			let output;
			if (opt_output) {
				output = opt_output;
			} else {
				if (dimension !== 2) {
					output = input.slice();
				} else {
					output = new Array(len);
				}
			}
			for (let offset = 0; offset < len; offset += dimension) {
				func(input, output, offset);
			}
			return output;
		};
	};

	/**
	 * 地球半径：WGS84坐标系
	 */
	const RADIUS = 6378137;
	const MAX_LATITUDE = 85.0511287798;
	const RAD_PER_DEG = Math.PI / 180;
	/**
	 * 球形墨卡托投影
	 */
	let sphericalMercator = {
		/**
		 * 正向
		 */
		forward: forEachPoint(function (input, output, offset) {
			let lat = Math.max(Math.min(MAX_LATITUDE, input[offset + 1]), -MAX_LATITUDE);
			let sin = Math.sin(lat * RAD_PER_DEG);

			output[offset] = RADIUS * input[offset] * RAD_PER_DEG;
			output[offset + 1] = RADIUS * Math.log((1 + sin) / (1 - sin)) / 2;
		}),

		/**
		 * 反向
		 */
		inverse: forEachPoint(function (input, output, offset) {
			output[offset] = input[offset] / RADIUS / RAD_PER_DEG;
			output[offset + 1] = (2 * Math.atan(Math.exp(input[offset + 1] / RADIUS)) - (Math.PI / 2)) / RAD_PER_DEG;
		}),
	};

	const MCBAND = [12890594.86, 8362377.87, 5591021, 3481989.83, 1678043.12, 0];
	const LLBAND = [75, 60, 45, 30, 15, 0];
	const MC2LL = [
		[1.410526172116255e-8, 0.00000898305509648872, -1.9939833816331, 200.9824383106796, -187.2403703815547, 91.6087516669843, -23.38765649603339, 2.57121317296198, -0.03801003308653, 17337981.2],
		[-7.435856389565537e-9, 0.000008983055097726239, -0.78625201886289, 96.32687599759846, -1.85204757529826, -59.36935905485877, 47.40033549296737, -16.50741931063887, 2.28786674699375, 10260144.86],
		[-3.030883460898826e-8, 0.00000898305509983578, 0.30071316287616, 59.74293618442277, 7.357984074871, -25.38371002664745, 13.45380521110908, -3.29883767235584, 0.32710905363475, 6856817.37],
		[-1.981981304930552e-8, 0.000008983055099779535, 0.03278182852591, 40.31678527705744, 0.65659298677277, -4.44255534477492, 0.85341911805263, 0.12923347998204, -0.04625736007561, 4482777.06],
		[3.09191371068437e-9, 0.000008983055096812155, 0.00006995724062, 23.10934304144901, -0.00023663490511, -0.6321817810242, -0.00663494467273, 0.03430082397953, -0.00466043876332, 2555164.4],
		[2.890871144776878e-9, 0.000008983055095805407, -3.068298e-8, 7.47137025468032, -0.00000353937994, -0.02145144861037, -0.00001234426596, 0.00010322952773, -0.00000323890364, 826088.5],
	];
	const LL2MC = [
		[-0.0015702102444, 111320.7020616939, 1704480524535203, -10338987376042340, 26112667856603880, -35149669176653700, 26595700718403920, -10725012454188240, 1800819912950474, 82.5],
		[0.0008277824516172526, 111320.7020463578, 647795574.6671607, -4082003173.641316, 10774905663.51142, -15171875531.51559, 12053065338.62167, -5124939663.577472, 913311935.9512032, 67.5],
		[0.00337398766765, 111320.7020202162, 4481351.045890365, -23393751.19931662, 79682215.47186455, -115964993.2797253, 97236711.15602145, -43661946.33752821, 8477230.501135234, 52.5],
		[0.00220636496208, 111320.7020209128, 51751.86112841131, 3796837.749470245, 992013.7397791013, -1221952.21711287, 1340652.697009075, -620943.6990984312, 144416.9293806241, 37.5],
		[-0.0003441963504368392, 111320.7020576856, 278.2353980772752, 2485758.690035394, 6070.750963243378, 54821.18345352118, 9540.606633304236, -2710.55326746645, 1405.483844121726, 22.5],
		[-0.0003218135878613132, 111320.7020701615, 0.00369383431289, 823725.6402795718, 0.46104986909093, 2351.343141331292, 1.58060784298199, 8.77738589078284, 0.37238884252424, 7.45],
	];

	/**
	 * 百度墨卡托投影
	 */
	window.baiduMercator = {
		resolutions: function () {
			let result = new Array(19);
			for (let i = 0; i < 19; ++i) {
				result[i] = Math.pow(2, 18 - i);
			}
			return result;
		},

		getRange: function (v, min, max) {
			v = Math.max(v, min);
			v = Math.min(v, max);

			return v;
		},

		getLoop: function (v, min, max) {
			let d = max - min;
			while (v > max) {
				v -= d;
			}
			while (v < min) {
				v += d;
			}

			return v;
		},

		convertor: function (input, output, offset, table) {
			let px = input[offset];
			let py = input[offset + 1];
			let x = table[0] + table[1] * Math.abs(px);
			let d = Math.abs(py) / table[9];
			let y = table[2]
				+ table[3] * d
				+ table[4] * d * d
				+ table[5] * d * d * d
				+ table[6] * d * d * d * d
				+ table[7] * d * d * d * d * d
				+ table[8] * d * d * d * d * d * d;
			output[offset] = x * (px < 0 ? -1 : 1);
			output[offset + 1] = y * (py < 0 ? -1 : 1);
		},

		forward: forEachPoint(function (input, output, offset) {
			let lng = baiduMercator.getLoop(input[offset], -180, 180);
			let lat = baiduMercator.getRange(input[offset + 1], -74, 74);
			let table = null;
			for (let j = 0; j < LLBAND.length; ++j) {
				if (lat >= LLBAND[j]) {
					table = LL2MC[j];
					break;
				}
			}
			if (table === null) {
				for (let j = LLBAND.length - 1; j >= 0; --j) {
					if (lat <= -LLBAND[j]) {
						table = LL2MC[j];
						break;
					}
				}
			}
			output[offset] = lng;
			output[offset + 1] = lat;
			baiduMercator.convertor(output, output, offset, table);
		}),

		inverse: forEachPoint(function (input, output, offset) {
			let y_abs = Math.abs(input[offset + 1]);
			let table = null;
			for (let j = 0; j < MCBAND.length; j++) {
				if (y_abs >= MCBAND[j]) {
					table = MC2LL[j];
					break;
				}
			}
			baiduMercator.convertor(input, output, offset, table);
		}),
	};

// 地球半径：北京54坐标系
	const RADIUS_BJ54 = 6378245.0;
	const OFFSET = 0.00669342162296594323;
	/**
	 * 火星坐标，国家测绘局02号标准，由于安全原因国家测绘局对真实坐标进行了加密处理，
	 * 腾讯、高德地图在用，以前的谷歌中国地图也在用。
	 */
	let gcj02 = {
		transformLat: function (x, y) {
			let ret = -100.0 + 2.0 * x + 3.0 * y + 0.2 * y * y + 0.1 * x * y + 0.2 * Math.sqrt(Math.abs(x));
			ret += (20.0 * Math.sin(6.0 * x * Math.PI) + 20.0 * Math.sin(2.0 * x * Math.PI)) * 2.0 / 3.0;
			ret += (20.0 * Math.sin(y * Math.PI) + 40.0 * Math.sin(y / 3.0 * Math.PI)) * 2.0 / 3.0;
			ret += (160.0 * Math.sin(y / 12.0 * Math.PI) + 320 * Math.sin(y * Math.PI / 30.0)) * 2.0 / 3.0;
			return ret;
		},

		transformLon: function (x, y) {
			let ret = 300.0 + x + 2.0 * y + 0.1 * x * x + 0.1 * x * y + 0.1 * Math.sqrt(Math.abs(x));
			ret += (20.0 * Math.sin(6.0 * x * Math.PI) + 20.0 * Math.sin(2.0 * x * Math.PI)) * 2.0 / 3.0;
			ret += (20.0 * Math.sin(x * Math.PI) + 40.0 * Math.sin(x / 3.0 * Math.PI)) * 2.0 / 3.0;
			ret += (150.0 * Math.sin(x / 12.0 * Math.PI) + 300.0 * Math.sin(x / 30.0 * Math.PI)) * 2.0 / 3.0;
			return ret;
		},

		delta: function (wgLon, wgLat) {
			let dLat = gcj02.transformLat(wgLon - 105.0, wgLat - 35.0);
			let dLon = gcj02.transformLon(wgLon - 105.0, wgLat - 35.0);
			let radLat = wgLat / 180.0 * Math.PI;
			let magic = Math.sin(radLat);
			magic = 1 - OFFSET * magic * magic;
			let sqrtMagic = Math.sqrt(magic);
			dLat = (dLat * 180.0) / ((RADIUS_BJ54 * (1 - OFFSET)) / (magic * sqrtMagic) * Math.PI);
			dLon = (dLon * 180.0) / (RADIUS_BJ54 / sqrtMagic * Math.cos(radLat) * Math.PI);
			return [dLon, dLat];
		},

		outOfChina: function (lon, lat) {
			if (lon < 72.004 || lon > 137.8347) {
				return true;
			}
			if (lat < 0.8293 || lat > 55.8271) {
				return true;
			}
			return false;
		},

		fromWGS84: forEachPoint(function (input, output, offset) {
			let lng = input[offset];
			let lat = input[offset + 1];
			if (!gcj02.outOfChina(lng, lat)) {
				let deltaD = gcj02.delta(lng, lat);
				lng = lng + deltaD[0];
				lat = lat + deltaD[1];
			}
			output[offset] = lng;
			output[offset + 1] = lat;
		}),

		toWGS84: forEachPoint(function (input, output, offset) {
			let lng = input[offset];
			let lat = input[offset + 1];
			if (!gcj02.outOfChina(lng, lat)) {
				let deltaD = gcj02.delta(lng, lat);
				lng = lng - deltaD[0];
				lat = lat - deltaD[1];
			}
			output[offset] = lng;
			output[offset + 1] = lat;
		}),
	};

	const X_PI = Math.PI * 3000 / 180;
	/**
	 * 百度坐标系(BD-09II)，基于火星坐标（GCJ-02）进行了再次加密处理
	 */
	let bd09 = {
		fromGCJ02: forEachPoint(function (input, output, offset) {
			let x = input[offset];
			let y = input[offset + 1];
			let z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * X_PI);
			let theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * X_PI);
			output[offset] = z * Math.cos(theta) + 0.0065;
			output[offset + 1] = z * Math.sin(theta) + 0.006;
			return output;
		}),

		toGCJ02: forEachPoint(function (input, output, offset) {
			let x = input[offset] - 0.0065;
			let y = input[offset + 1] - 0.006;
			let z = Math.sqrt(x * x + y * y) - 0.00002 * Math.sin(y * X_PI);
			let theta = Math.atan2(y, x) - 0.000003 * Math.cos(x * X_PI);
			output[offset] = z * Math.cos(theta);
			output[offset + 1] = z * Math.sin(theta);
			return output;
		}),

		fromWGS84: function (input, opt_output, opt_dimension) {
			let output = gcj02.fromWGS84(input, opt_output, opt_dimension);
			return bd09.fromGCJ02(output, output, opt_dimension);
		},

		toWGS84: function (input, opt_output, opt_dimension) {
			let output = bd09.toGCJ02(input, opt_output, opt_dimension);
			return gcj02.toWGS84(output, output, opt_dimension);
		},
	};

	/**
	 * 投影变换
	 */
	window.projTransform = {
		smerc2bmerc: function (input, opt_output, opt_dimension) {
			let output = sphericalMercator.inverse(input, opt_output, opt_dimension);
			output = bd09.fromWGS84(output, output, opt_dimension);
			return baiduMercator.forward(output, output, opt_dimension);
		},

		bmerc2smerc: function (input, opt_output, opt_dimension) {
			let output = baiduMercator.inverse(input, opt_output, opt_dimension);
			output = bd09.toWGS84(output, output, opt_dimension);
			return sphericalMercator.forward(output, output, opt_dimension);
		},

		bmerc2ll: function (input, opt_output, opt_dimension) {
			let output = baiduMercator.inverse(input, opt_output, opt_dimension);
			return bd09.toWGS84(output, output, opt_dimension);
		},

		ll2bmerc: function (input, opt_output, opt_dimension) {
			console.log('ll2bmerc', '-input:', input, '-opt_output:', opt_output, '-opt_dimension:', opt_dimension);
			let output = bd09.fromWGS84(input, opt_output, opt_dimension);
			return baiduMercator.forward(output, output, opt_dimension);
		},

		ll2smerc: function (input, opt_output, opt_dimension) {
			return sphericalMercator.forward(input, opt_output, opt_dimension);
		},

		smerc2ll: function (input, opt_output, opt_dimension) {
			return sphericalMercator.inverse(input, opt_output, opt_dimension);
		},
	};
})(window);



